private void FlipValidTriominoAndSetStep(ETriomino triomino, int x, int y, int depth)
{
Steps[depth].triomino = triomino;
Steps[depth].x = x;
Steps[depth].y = y;
Steps[depth].placed = !Steps[depth].placed;
++StepsTaken;
FlipValidTriomino(triomino, x + y * Width);
}
private IEnumerator CalculateCoroutine(int x, int y, int depth)
{
if (m_UseMem && m_Dictionary.TryGetValue(m_State, out long permutations))
{
Permutations += permutations;
//FlipValidTriominoAndSetStep(ETriomino.Mem, 0, 0, depth);
yield return(null);
}
else
{
long prevPermutations = Permutations;
int index = x + y * Width;
//Find index for next piece to be placed
while (!m_State[index])
{
++index;
}
//Find next piece to be placed at the index
int nextX = index % Width;
int nextY = index / Width;
int nextDepth = depth + 1;
ETriomino next = GetNextValidTriomino(ETriomino.None, nextX, nextY);
while (next != ETriomino.None)
{
FlipValidTriominoAndSetStep(next, nextX, nextY, depth);
yield return(null);
if (nextDepth == m_MaxPieces)
{
Permutations += 1L;
}
else
{
IEnumerator e = CalculateCoroutine(nextX, nextY, nextDepth);
while (e.MoveNext())
{
yield return(null);
}
}
FlipValidTriominoAndSetStep(next, nextX, nextY, depth);
yield return(null);
next = GetNextValidTriomino(next, nextX, nextY);
}
if (m_UseMem && (prevPermutations != Permutations))
{
m_Dictionary.Add((DynamicBitset)m_State.Clone(), Permutations - prevPermutations);
}
}
}
/// <summary>
/// Flips the bits corresponding the the specific triomino piece at the specified location
/// Does not do any bounds checking for additional performance gains
/// </summary>
/// <param name="triomino">The piece being placed or removed</param>
/// <param name="index">The location in the bitset the piece is being placed or removed/param>
private void FlipValidTriomino(ETriomino triomino, int index)
{
switch (triomino)
{
case ETriomino.None:
return;
case ETriomino.VLine:
m_State.Flip(index);
m_State.Flip(index + Width);
m_State.Flip(index + (Width << 1));
return;
case ETriomino.TopLeft:
m_State.Flip(index);
m_State.Flip(index + Width);
m_State.Flip(index + 1);
return;
case ETriomino.TopRight:
m_State.Flip(index);
m_State.Flip(index + 1);
m_State.Flip(index + 1 + Width);
return;
case ETriomino.BottomLeft:
m_State.Flip(index);
m_State.Flip(index + Width);
m_State.Flip(index + 1 + Width);
return;
case ETriomino.BottomRight:
m_State.Flip(index);
m_State.Flip(index + Width);
m_State.Flip(index + Width - 1);
return;
case ETriomino.HLine:
m_State.Flip(index);
m_State.Flip(index + 1);
m_State.Flip(index + 2);
return;
default:
return;
}
}
private long Calculate(int index, int depth)
{
long total = 0;
if (m_Dictionary.TryGetValue(m_State, out long prevPermutations))
{
total += prevPermutations;
}
else
{
//Find index for next piece to be placed
while (!m_State[index])
{
++index;
}
//Find next piece to be placed at the index
int nextX = index % Width;
int nextY = index / Width;
int nextDepth = depth + 1;
ETriomino next = GetNextValidTriomino(ETriomino.None, nextX, nextY);
while (next != ETriomino.None)
{
if (nextDepth == m_MaxPieces)
{
total += 1;
}
else
{
FlipValidTriomino(next, index);
total += Calculate(index, nextDepth);
FlipValidTriomino(next, index);
}
next = GetNextValidTriomino(next, nextX, nextY);
}
if (total != 0)
{
m_Dictionary.Add((DynamicBitset)m_State.Clone(), total);
}
}
return(total);
}
private ETriomino GetNextValidTriomino(ETriomino triomino, int x, int y)
{
bool b01 = ((y + 1) < Height) && State(x, y + 1);
bool b10 = ((x + 1) < Width) && State(x + 1, y);
bool b11 = ((y + 1) < Height) && ((x + 1) < Width) && State(x + 1, y + 1);
switch (triomino)
{
case ETriomino.None:
if (b01 && ((y + 2) < Height) && State(x, y + 2))
{
return(ETriomino.VLine);
}
else
{
goto case ETriomino.VLine;
}
case ETriomino.VLine:
if (b10 && b01)
{
return(ETriomino.TopLeft);
}
else
{
goto case ETriomino.TopLeft;
}
case ETriomino.TopLeft:
if (b10 && b11)
{
return(ETriomino.TopRight);
}
else
{
goto case ETriomino.TopRight;
}
case ETriomino.TopRight:
if (b01 && b11)
{
return(ETriomino.BottomLeft);
}
else
{
goto case ETriomino.BottomLeft;
}
case ETriomino.BottomLeft:
if (b01 && (x > 0) && State(x - 1, y + 1))
{
return(ETriomino.BottomRight);
}
else
{
goto case ETriomino.BottomRight;
}
case ETriomino.BottomRight:
if (b10 && ((x + 2) < Width) && State(x + 2, y))
{
return(ETriomino.HLine);
}
else
{
return(ETriomino.None);
}
case ETriomino.HLine:
return(ETriomino.None);
case ETriomino.Mem:
return(ETriomino.None);
default:
return(ETriomino.None);
}
}
